Hiroshima Carp infielder Takahiro Arai on Wednesday announced he will retire from baseball at the end of the 2018 season, drawing the curtain on his 20-year playing career.

The 41-year-old, who started his professional career with the Carp in 1999, said he decided to hang up his cleats after failing to meet the fans' expectations. He has a .222 batting average over 49 games this season.

"I feel bad letting my fans down. Considering where the Carp are heading, I felt this year would be best," Arai said in a press conference at Mazda Stadium.

"I've been blessed to be surrounded by amazing people for 20 years. Playing for four years after coming back to Hiroshima wanting to help the Carp in any way possible, and winning the (Central League) titles...I only have feelings of appreciation," he said.

After nine years with the Carp, Arai signed with the Hanshin Tigers as a free agent in 2008 and spent the next seven seasons with the Carp's CL rivals.

In 2015, he returned to Hiroshima and was part of the team that won the franchise's first league pennant in 25 years in 2016, the year he was named the CL MVP.

The following year he contributed to the Carp's second straight CL championship as a pinch hitter. The Carp, who are looking for a record three-peat this season, are currently leading the six-team CL standings.

"There's not a lot of things I have to say about his decision," Carp skipper Koichi Ogata said. "We're gearing up toward a league championship, and a Japan championship. When all that's done, I will say all those things."

As of Tuesday, Arai is hitting .278 with 2,200 hits, including 319 homers, and 1,299 RBIs in 2,369 games over his career.

Hiroshima Carp owner Hajime Matsuda said he could not make Arai reconsider his decision to retire as he is "a man who thinks with his heart," saying he wants the club to send him off with a Japan Series win.

Arai said there was no one reason for his decision, but suggested he did not want to stand in the way of young teammates who were ready to play.

"It's a combination of things. One is that we have developed young players, and after thinking about various things, I thought that perhaps this was the year," Arai said.

Former ace Hiroki Kuroda, who returned to Hiroshima from the big leagues the same season Arai returned from Hanshin, was surprised by the timing but not his former teammate's reasoning.

"When I first heard, it was a shock," said Kuroda, who retired after the 2016 Japan Series. "Making a decision based on the team's needs and those of the young players, that is so like him."